You may have heard this referred to as "Lawn mover pulls" because the moment mimics that of starting your lawn mower. This movement can be done with one knee on a bench, but I prefer it standing bracing my hand on something about waist level- the incline bench works great!
Picking the weight up, let it hang straight down. When you pull it up, pull back toward your hit isolating your lower lat. Squeeze at the top of the rep and let it down slowing stretching your back out.